As is known in the art, some existing automotive radar systems detect targets which produce a radar return signal having a signal strength which exceeds a threshold signal strength in range/Doppler space. The radar then develops an estimate of X-Y position and velocity for each target. This approach typically requires algorithms in the form of state machines and tracking with thresholds and heuristics.
Referring to FIGS. 1-1A, some conventional automotive radar systems use two antennas, each feeding one channel of a two-channel receiver. As illustrated in FIG. 1A, the phase difference between the signals in the two channels provides angle information which can be used to detect targets in an azimuth plane. An antenna spacing of one-half wavelength (λ/2) theoretically enables such a two-channel automotive radar system to provide unambiguous angle information over a 180° field of view (FOV).